Trends in use of e cigarette device types and heated tobacco products from 2016 to 2020 in England
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OPEN Trends in use of e‑cigarette device
types and heated tobacco products
from 2016 to 2020 in England
Harry Tattan‑Birch*, Jamie Brown, Lion Shahab & Sarah E. Jackson
This study examined use trends of e-cigarette devices types, heated tobacco products (HTPs) and
e-liquid nicotine concentrations in England from 2016 to 2020. Data were from a representative repeat
cross-sectional survey of adults aged 16 or older. Bayesian logistic regression was used to estimate
proportions and 95% credible intervals (CrIs). Of 75,355 participants, 5.3% (weighted = 5.5%) were
currently using e-cigarettes or HTPs, with the majority (98.7%) using e-cigarettes. Among e-cigarette
users, 53.7% (CrI 52.0–55.1%) used tank devices, 23.7% (22.4–25.1%) mods, 17.3% (16.1–18.4%) pods,
and 5.4% (4.7–6.2%) disposables. Tanks were the most widely used device type throughout 2016–
2020. Mods were second until 2020, when pods overtook them. Among all e-cigarette/HTP users,
prevalence of HTP use remains rare (3.4% in 2016 versus 4.2% in 2020), whereas JUUL use has risen
from 3.4% in 2018 to 11.8% in 2020. Across all years, nicotine concentrations of ≤ 6 mg/ml were most
widely (41.0%; 39.4–42.4%) and ≥ 20 mg/ml least widely used (4.1%; 3.4–4.9%). Among e-cigarette/
HTP users, ex-smokers were more likely than current smokers to use mod and tank e-cigarettes, but
less likely to use pods, disposables, JUUL and HTPs. In conclusion, despite growing popularity of pods
and HTPs worldwide, refillable tank e-cigarettes remain the most widely used device type in England.
Heated aerosolized nicotine delivery systems (HANDS) are handheld devices that heat either nicotine-infused
liquid or tobacco sticks, producing an aerosol that can be inhaled. These include electronic cigarettes (“e-cig-
arettes”) and heated tobacco products (HTPs). Over the past decade, HANDS—principally e-cigarettes—have
eclipsed nicotine replacement therapy as the most widely used aids for stopping smoking in England1. e-Ciga-
rettes encompass a variety of different products, from bulky mod e-cigarettes to small cigarette shaped cigalikes.
These can vary considerably in their potential to produce toxicants and carcinogens2, delivery of nicotine3,4, and
effectiveness in helping people stop smoking combustible c igarettes5–7. It is therefore important to explore how
the number of people using different device types and nicotine concentrations is changing, alongside a regulatory
environment that may incentivise or discourage use of certain products. In this paper, we explore trends in the
use of different e-cigarette device types and heated tobacco products in England, from 2016 to 2020.
e‑Cigarette device type. The most commonly used form of HANDS in England are e-cigarettes: hand-
held electronic devices that heat a liquid, called an e-liquid, in order to produce an aerosol for inhalation.
e-Liquid usually contains nicotine alongside propylene glycol, glycerol and flavourings. e-Cigarette use is widely
recognised as less harmful to health than cigarette smoking, since users are exposed to much lower levels of
toxicants and carcinogens2,8,9. However, public health bodies have differing attitudes towards the overall impact
of e-cigarettes on public health, with some emphasising their potential use for smoking cessation while others
highlighting risks to young non-smokers10. The UK has taken a policy approach that attempts to benefit from the
use of e-cigarettes for smoking cessation, while minimising risks from youth u se11. Evidence from randomised
controlled trials5,7,12 and observational studies1,13 indicates that nicotine e-cigarettes can increase the likelihood
that people will succeed in their attempts to stop smoking cigarettes. But their effectiveness for smoking cessa-
tion may depend on the specific device used.
Disposable cigarette shaped devices, also known as cigalikes, were the first type of e-cigarette to enter the
market in England. Compared with newer devices, these deliver less n icotine4 and, as a result, may be less effec-
6
tive at helping people quit smoking .
Tank e-cigarettes have a rechargeable battery and a tank that can be replenished with bottled e-liquid. They
come in a variety of shapes, but most are the size of a fountain pen. These refillable tank devices tend to have a
fixed power output, so the temperature to which e-liquid is heated remains relatively constant. They can deliver
Department of Behavioural Science and Health, Institute of Epidemiology and Health Care, University College
London, 1‑19 Torrington Place, Fitzrovia, London WC1E 7HB, UK. *email: h.tattan-birch@ucl.ac.uk
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a similar amount of nicotine to cigarettes and satisfy cravings to smoke14. Two recent randomised controlled
trials demonstrated the effectiveness of tank e-cigarettes for smoking cessation. The first found that they almost
doubled the rate of successfully quitting smoking after 12 months when compared with nicotine replacement
therapy5. The second found that, when used in conjunction with nicotine patches, tank e-cigarettes increased
abstinence when compared to nicotine patches used alone or with placebo e-cigarettes12.
Modified or modular (“mod”) e-cigarettes are assembled by users from a variety of parts (e.g. atomizers and
batteries). These are also refillable and rechargeable; however, they often have variable power output. This means
that users can adjust the temperature to which their e-liquid is heated and, thus, the amount of vapour and nico-
tine they inhale. This can be problematic because hotter e-liquid makes the production of carcinogenic carbonyls,
like formaldehyde, more l ikely2. However, most users find the aerosol produced at these hotter temperatures to
be aversive, so are unlikely to vape with such high power settings15.
Pod devices are the most recent type of e-cigarette to enter the market in England. These are small, low pow-
ered, rechargeable e-cigarettes that use disposable cartridges (or “pods”) full of e-liquid. Because of their low
power output, the nicotine concentration in pod e-liquid usually needs to be much higher than in mod devices
to produce the same amount of nicotine per puff16. They produce less vapour and lower carbonyl yields than
higher powered d evices17. We will also look specifically into use of one brand of pod e-cigarettes: JUUL. JUUL,
a manufacturer of sleek pod e-cigarettes, has received intense scrutiny because of the rapid growth in popular-
ity of their devices in the US, especially among young people18. JUUL were among the first to use e-liquids that
contain nicotine salts rather than freebase nicotine. This nicotine salts formulation has a pH that is more similar
to the extravascular fluid in the lung, allowing users to vape much higher concentrations of nicotine without
experiencing irritation to the throat, which may explain their p opularity3,19. Other pod manufacturers followed
suit, adding nicotine salts to e-liquid in their cartridges20. Laboratory results show that pods using nicotine salts
reduce urges to smoke more rapidly than other types of e-cigarettes, which might make them more effective at
helping people quit smoking3,20. JUUL launched in England in the summer of 201821.
In this study, we will explore how the proportion of people in England using disposable, tank, mod, and pod
(including JUUL specifically) devices has changed from 2016 to 2020.
Nicotine concentration. The amount of nicotine that vapers receive from their e-cigarette per puff depends
on the nicotine concentration of the e-liquid, features of the device, such as power output and wick material,
and the duration and strength with which they puff. Experimental evidence shows that people self-titrate their
nicotine consumption when vaping, such that those who use low nicotine concentration e-liquids tend to puff
on their device more often and for longer in order to achieve their desired nicotine intake and, as a result, inhale
a greater volume of aerosol22. Moreover, people who use variable power devices can raise the temperature of
their device, which increases e-liquid consumption and formaldehyde p roduction22,23. Therefore, it is important
to track how the popularity of various nicotine concentrations is changing in England, within the context of EU
TPD regulation that limits nicotine concentration in e-liquid to ≤ 20 mg/ml. This nicotine cap may also influence
the popularity of different device types. Most notably, it could suppress use of pod e-cigarettes, like JUUL, that
are sold at much higher concentrations (up to 59 mg/ml) in countries without such regulations.
Heated tobacco products. Another form of HANDS with growing popularity globally are heated (or
“heat-not-burn”) tobacco products24, such as IQOS by Philip Morris International. These are handheld devices
that heat tobacco to a high enough temperature to produce a nicotine-infused aerosol, but thought to be too low
to cause combustion25. Toxins produced by burning tobacco are the primary cause of harm from cigarettes, so
avoiding combustion likely substantially lowers the risk of tobacco-related d iseases26. Unlike e-cigarettes, heated
tobacco products contain tobacco leaf. Their flavour may more closely resemble cigarette s moke27, which could
make them more appealing to smokers trying to quit. Before their entrance into the UK market in late 2016,
heated tobacco products had become very popular in Japan and South Korea, and made up 15.8% and 8.0% of
each country’s respective tobacco sales in 2 01824. Yet, at least initially, the use of heated tobacco products was
rare in England26. Here, we will explore whether the prevalence of heated tobacco product use in England has
grown since 2017.
Frequency of use. Along with other factors such as reason for v aping28–30, the effectiveness of e-cigarettes
for smoking cessation likely depends on how frequently smokers use their e-cigarette: people who use e-ciga-
rettes daily have higher odds of subsequently quitting smoking when compared with less frequent u sers31. There-
fore, we will explore how use of different devices and nicotine concentrations vary between daily and non-daily
HANDS users.
Differences by smoking status. Vapers who also smoke (54%) might use different types of e-cigarettes
than those who have quit smoking (40%) or never smoked (6%)32. For instance, devices that do not help people
quit smoking would be rarely used by ex-smokers, because smokers who use them would be unlikely to transi-
tion to sole e-cigarette use. In this study, we investigate whether HANDS users who also smoke use different
e-cigarette device types, heated tobacco products and nicotine concentrations than those who are former or
never smokers.
Research aims. To summarise, we aim to measure annual trends from 2016 to 2020 in England in:
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1. the proportion of HANDS users who use different types of e-cigarette devices (e.g. tank devices) or heated
tobacco products, and
2. the proportion of e-cigarette users who use e-liquids of various nicotine concentrations.
We also aim to compare how use of these products differs between (1) daily and non-daily HANDS users,
and (2) HANDS users who are smokers, ex-smokers and never smokers.
Methods
Design. Data came from the Smoking Toolkit Study (STS), a monthly repeated cross-sectional survey that
provides detailed information on smoking behaviours and e-cigarette use in England. Using a combination of
random location and quota sampling, it recruits approximately 1700 participants per month33. Comparisons
with other national surveys and sales data show that the STS recruits a representative sample of the population
in England34,35. Ethical approval was provided by the UCL Research Ethics Committee (0498/001). Participants
gave informed consent to take part in the study. All participants were at least the age required (≥ 16 years) to give
informed consent under UK Health Research Authority guidelines36. All methods were carried out in accord-
ance with relevant regulations and guidelines.
Study sample. Adults aged ≥ 16 years who reported that they were currently using e-cigarettes or heated
tobacco products (HTPs). Data were included from July 2016, the month where detailed e-cigarette usage char-
acteristics were first recorded, through February 2020. Questions about use of JUUL and heated tobacco prod-
ucts were added to the survey in July 2018 and December 2016, respectively.
Measures. Type of e‑cigarette or heated tobacco product. Participants were asked a series of questions about
whether they currently use e-cigarettes, JUUL and/or heated tobacco products to cut down the amount they
smoke, in situations when they are not allowed to smoke, to help them stop smoking, or for any other reason at
all. Their responses were categorised as follows:
– e-Cigarette user—“Electronic cigarette”
– Heated tobacco product user—“heat-not-burn cigarette (e.g. iQOS with HEETS, heatsticks)”
– JUUL user—“JUUL”
e-Cigarette (non-JUUL) users were asked a follow-up question about the specific device(s) they used: “Which
of the following do you mainly use…?” They could respond:
– Disposable—“A disposable e-cigarette or vaping device (non-rechargeable)”
– Tank—“An e-cigarette or vaping device with a tank that you refill with liquids (rechargeable)”
– Mod—“A modular system that you refill with liquids (you use your own combination of separate devices:
batteries, atomizers, etc.)”
– Pod—“An e-cigarette or vaping device that uses replaceable pre-filled cartridges (rechargeable)”
Frequency of use. HANDS users were asked: “How many times per day on average do you use your nicotine
replacement product or products?” Those who reported using their e-cigarette or heated tobacco product at least
once a day were classified as daily users. All others were considered non-daily users.
Nicotine concentration. e-Cigarette users (non-JUUL) were asked: “Does the electronic cigarette or vaping
device you mainly use contain nicotine?” They could respond “yes”, “no”, or “don’t know”.
Participants who reported using a non-JUUL e-cigarette with nicotine were asked: “What strength is the
e-liquid that you mainly use in your electronic cigarette or vaping device?”. They could respond:
– “6 mg/ml (~ 0.6%) or less”
– “7 mg/ml (~ 0.7%) to 11 mg/ml (~ 1.1%)”
– “12 mg/ml (~ 1.2%) to 19 mg/ml (~ 1.9%)”
– “20 mg/ml (~ 2.0%) or more”
– “Don’t know”
Source of purchase. We also measured trends in the types of vaping retailer that were most widely used by
e-cigarette users. Details of these analyses are available in the “Supplementary material”.
Smoking status. Participants were asked which of the following best applied to them.
a) “I smoke cigarettes (including hand-rolled) every day”
b) “I smoke cigarettes (including hand-rolled), but not every day”
c) “I do not smoke cigarettes at all, but I do smoke tobacco of some kind (e.g. pipe, cigar or shisha)”
d) “I have stopped smoking completely in the last year”
e) “I stopped smoking completely more than a year ago”
f) “I have never been a smoker (i.e. smoked for a year or more)”
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Those who reported currently smoking cigarettes or tobacco of another kind (responses a–c) were considered
smokers, and those who reported stopping smoking within the last year or more than a year ago (responses d,
e) were considered ex-smokers. All others (response f) were considered never-smokers.
Socio‑demographic characteristics. Age, gender, ethnicity (white, minority ethnic), and occupation-based
social grade (C2DE includes manual routine, semi-routine, lower supervisory, and long-term unemployed;
ABC1 includes managerial, professional and upper supervisory occupations37) were recorded.
Analysis. Analytic strategy. The analysis was conducted in R and S tan38,39. The pre-registered analysis plan
is available on the Open Science Framework (https://osf.io/57fvd/). Bayesian inference was used throughout,
which allowed us to (1) report the relative plausibility of parameter values given the model and data and (2)
include weakly informative priors, which regularise estimates and thus reduce the risk of o verfitting40. Following
41
a conservative a pproach , priors were selected using prior predictive simulation (details available on https://
osf.io/57fvd/). 95% credible intervals (95% CIs) represent highest posterior density intervals. We only analysed
cases with complete information on all the variables that were included in each model. Survey weights were ap-
plied to calculate the overall prevalence of HANDS use among adults. All other analyses were unweighted, as
they were calculated from a small subsample of the population (current HANDS users).
Sample characteristics. The proportion of people with different socio-demographic characteristics who used
each device type were reported descriptively.
Device type. We estimated the total proportion of HANDS users who reported using each different device type.
To explore how device usage changed from 2016 to 2020, we constructed logistic regression models with year of
survey as an explanatory variable. From these models, we reported the proportion of HANDS users who used
each device type in each year, alongside 95% CIs. We then stratified by frequency of use, to compare relative risk
(RR) of use of each device type between daily and non-daily users, excluding participants who used combina-
tions of device types or nicotine replacement therapy (NRT).
Nicotine concentration. We estimated the total proportion of e-cigarette users who reported using each of the
different nicotine concentrations listed in the measures section. We again constructed logistic models with year
of survey as an explanatory variable. Yearly estimates of the proportion of e-cigarette users who used each nico-
tine concentration were reported alongside 95% CrIs. We then stratified by frequency of use, to compare daily
vs. non-daily use of each nicotine concentration. Finally, we presented the proportion of users of each device
type who used each nicotine concentration of e-liquid, excluding participants who used combinations of device
types.
Difference by smoking status. To test whether there were differences in device type or nicotine concentration
use between smokers, ex-smokers and never smokers, we constructed a set of logistic regression models for each
outcome including smoking status as an explanatory variable.
Results
Of the 75,355 adults who responded to the Smoking Toolkit Study between August 2016 and February 2020,
3786 (unweighted = 5.29%, weighted = 5.53%; 95% CrI 5.45–5.62%) reported currently using HANDS, and this
prevalence remained relatively stable from 2016 to 2020 (see Supplementary Fig. S2). Socio-demographic infor-
mation for users of each device type are shown in Table 1.
Device type. Overall, e-cigarettes were used by 98.7% (95% CrI 98.4–99.0%) of HANDS users and heated
tobacco products by 2.2% (1.8–2.7%). Among e-cigarette users, 53.7% (52.0–55.1%) used tank devices, 23.7%
(22.4–25.1%) used mods, 17.3% (16.1–18.4%) used pods, and 5.4% (4.7–6.2%) used disposables. JUUL e-ciga-
rettes were used by 5.1% (4.1–6.1%) of HANDS users.
Figure 1 shows trends in the prevalence of usage of different device types among HANDS users from 2016 to
2020. In general, use of different device types remained stable over time, with tank e-cigarette consistently the
most widely used device type. Mod e-cigarettes were the second most commonly used device type until 2020,
when pods overtook them. Use of JUUL has risen from 3.4% (2.1–5.3%) of HANDS users in 2018 to 11.8%
(7.8–17.6%) in 2020. Heated tobacco product use has remained rare—with 3.4% (1.2–8.0%) of HANDS users
using them in 2016 versus 4.2% (2.2–7.5%) in 2020. Relative to non-daily e-cigarette users, daily users were
more likely to use tank devices, equally likely to use mods, but less likely to use disposables or pods (Table 2).
HANDS users who currently smoked were less likely than those who never smoked to use JUUL and heated
tobacco products, but more likely to use pods. Conversely, they were less likely to use mod and tank e-cigarettes
than ex-smokers, but more likely to use pods, disposables, JUUL and heated tobacco products.
Nicotine concentration. The most widely used nicotine concentration was ≤ 6 mg/ml, used by 41.0%
(39.4–42.4%) of e-cigarette users. This was followed by 12–19 mg/ml used by 23.4% (21.8–24.9%), 7–11 mg/ml
by 13.4% (12.0–14.6%), no nicotine by 14.2% (13.2–15.1%), ≥ 20 mg/ml by 4.1% (3.4–4.9%), and do not know
by 3.2% (2.6–3.8%). Figure 2 shows trends in use of different concentrations from 2016 to 2020. Use of different
nicotine concentrations remained relatively stable, with ≤ 6 mg/ml being the most widely used concentration
across all years. Relative to non-daily e-cigarette users, daily users were less likely to use non-nicotine e-liquid
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Among adults (n = 75,355) Among HANDSa users (n = 3786)
Any HANDS Disposable Pod Tank Mod JUULb HTPc
Age (years)
16–17 32 (2.9%) 1 (3.1%) 6 (18.8%) 18 (56.2%) 5 (15.6%) 1 (16.7%) 0 (0.0%)
18–24 554 (5.6%) 29 (5.2%) 76 (13.7%) 282 (50.9%) 121 (21.8%) 30 (12.1%) 8 (1.6%)
25–34 817 (7.7%) 33 (4.0%) 94 (11.5%) 414 (50.7%) 225 (27.5%) 13 (3.4%) 14 (1.9%)
35–44 711 (6.8%) 40 (5.6%) 112 (15.8%) 343 (48.2%) 163 (22.9%) 4 (1.4%) 19 (3.1%)
45–54 760 (6.9%) 34 (4.5%) 122 (16.1%) 397 (52.2%) 152 (20.0%) 10 (3.1%) 14 (2.1%)
55–64 636 (5.5%) 30 (4.7%) 123 (19.3%) 309 (48.6%) 129 (20.3%) 9 (3.1%) 10 (1.8%)
65+ 463 (2.3%) 34 (7.3%) 102 (22.0%) 203 (43.8%) 76 (16.4%) 20 (9.3%) 12 (2.9%)
Gender
Men 2192 (5.8%) 116 (5.3%) 313 (14.3%) 1087 (49.6%) 510 (23.3%) 56 (5.7%) 37 (1.9%)
Women 1787 (4.7%) 85 (4.8%) 323 (18.1%) 880 (49.2%) 362 (20.3%) 34 (4.4%) 41 (2.6%)
Ethnicity
White 3630 (5.7%) 177 (4.9%) 569 (15.7%) 1823 (50.2%) 807 (22.2%) 68 (4.3%) 63 (2.0%)
Minority ethnic 343 (3.2%) 24 (7.0%) 64 (18.7%) 145 (42.3%) 61 (17.8%) 22 (12.2%) 14 (4.6%)
Social grade
ABC1 2044 (4.5%) 83 (4.1%) 337 (16.5%) 1008 (49.3%) 445 (21.8%) 66 (7.1%) 37 (2.1%)
C2DE 1942 (6.5%) 118 (6.1%) 299 (15.4%) 964 (49.6%) 427 (22.0%) 24 (2.9%) 41 (2.4%)
Table 1. Sample characteristics by type of device used (n = 3786). The percentage who used each different
device type are shown in brackets. People could report that they used multiple products. a Heated aerosolized
nicotine delivery systems (HANDS) include e-cigarettes and heated tobacco products. b The denominator used
to calculate percentages in this column was the number of HANDS users surveyed from July 2018—the month
in which JUUL use began being recorded—to February 2020 (n = 1760). c The denominator used to calculate
percentages in this column was the number of HANDS users surveyed from December 2016—the month in
which heated tobacco products (HTPs) use began being recorded—to February 2020 (n = 3520).
60%
Percentage of HANDS Users
Tank
Pod
40%
Mod
Juul
Disposable
20% HTP
0%
2016 2017 2018 2019 2020
Year
Figure 1. Use of different e-cigarette device types and heated tobacco product use among adult heated
aerosolized nicotine delivery system (HANDS) users in England from 2016 to 2020. Shaded bands represent
95% CrIs. Trends would be the same with a denominator of all adults rather than only HANDS users, as overall
prevalence of HANDS use was stable from 2016 to 2020 (Supplementary Fig. S2). Some people reported using
JUUL but not pods. When these individuals were considered pod users, there was a more pronounced rise in
pod use from 19.5% in 2019 to 30.4% in 2020.
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Disposable (95% CrI) Pod (95% CrI) Tank (95% CrI) Mod (95% CrI) JUULa (95% CrICrI) HTPb (95% CrI)
Frequency of use c
Non-daily (N = 938)
% 6.0 (4.5–7.6) 21.5 (18.9–24.4) 48.9 (45.8–51.9) 23.3 (20.8–26.1) – –
RRd Ref Ref Ref Ref – –
Daily (N = 2337)
% 4.1 (3.4–4.9) 14.3 (12.9–15.7) 57.4 (55.4–59.2) 24.1 (22.5–25.6) – –
RR 0.70 (0.48–0.92) 0.67 (0.57–0.78) 1.18 (1.09–1.25) 1.03 (0.91–1.17) – –
Smoking status
Smoker (N = 2354)
% 6.1 (5.1–7.3) 19.3 (17.7–20.9) 51.0 (48.9–53.0) 22.5 (21.0–24.3) 4.3 (3.2–5.8) 2.6 (2.0–3.3)
RR Ref Ref Ref Ref Ref Ref
Never smoker (N = 264)
% 6.0 (3.5–10.2) 13.7 (9.8–18.8) 53.1 (47.3–59.0) 28.1 (22.5–34.6) 26.8e (20.2–34.6) 4.9 (2.9–8.3)
RR 1.02 (0.52–1.65) 0.72 (0.50–0.97) 1.04 (0.92–1.16) 1.26 (0.99–1.57) 6.32 (3.89–8.82) 1.96 (0.95–3.05
Ex-smoker (N = 1364)
% 2.6 (1.9–3.7) 14.3 (12.6–16.3) 58.1 (55.1–60.9) 25.0 (22.6–27.4) 1.6 (0.9–2.9) 1.1 (0.6–1.7)
RR 0.44 (0.28–0.61) 0.75 (0.63–0.86) 1.14 (1.06–1.21) 1.11 (0.98–1.26) 0.39 (0.16–0.67) 0.43 (0.21–0.65)
Table 2. Device type use by frequency of use and smoking status among people who reported using HANDS.
Heated aerosolized nicotine delivery systems (HANDS) include e-cigarettes and heated tobacco products.
Percentages are unweighted. a Use of JUUL was recorded from July 2018 (n = 1760). Frequency could not be
assessed as all JUUL users had used combinations of products. b Use of heated tobacco products (HTPs) was
recorded from December 2016 (n = 3520). Frequency could not be assessed as all but one HTP user used
combinations of products. c Participants who used combinations of products or NRT were excluded. d RR
represent risk ratio. e The high prevalence of JUUL use among never smoking HANDS users was primarily
driven by data from a single month in a specific local authority area. Therefore, it likely represents a localised
effect.
Percentage of E-cigarette Users
40%
≤6mg/ml
12-19mg/ml
7-11mg/ml
No nicotine
20%
≥20mg/ml
0%
2016 2017 2018 2019 2020
Year
Figure 2. Nicotine concentration used in e-cigarettes by adult e-cigarette users in England from 2016 to 2020.
Shaded bands represent 95% CrIs. Trends would be the same with a denominator of all adults rather than only
e-cigarette users, as overall prevalence of e-cigarette use was stable from 2016 to 2020 (Supplementary Fig. S2).
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No nicotinic (95% ≤ 6 mg/ml (95% 7–11 mg/ml (95% 12–19 mg/ml (95% ≥ 20 mg/ml (95% Do not know
CrI) CrI) CrI) CrI) CrI) (95% CrI)
Frequency of usea
Non-daily (N = 938)
% 18.4 (16.3–20.5) 37.7 (35.0–40.6) 14.9 (13.1–16.9) 17.7 (15.7–19.8) 4.5 (3.5–5.9) 5.4 (4.3–6.7)
RRb Ref Ref Ref Ref Ref Ref
Daily (N = 2337)
% 12.1 (11.0–13.4) 42.5 (40.6–44.2) 12.6 (11.4–14.0) 26.0 (24.4–27.6) 4.0 (3.3–4.8) 2.3 (1.8–3.0)
RR 0.66 (0.56–0.77) 1.13 (1.04–1.24) 0.85 (0.73–0.99) 1.47 (1.27–1.66) 0.89 (0.59–1.16) 0.44 (0.31–0.59)
Device typec
Disposable (N = 153)
% 21.9 (16.6–28.5) 31.3 (24.8–38.8) 16.4 (11.1–22.9) 20.4 (14.9–27.1) 1.4 (0.4–3.6) 7.4 (4.1–12.4)
RR Ref Ref Ref Ref Ref Ref
Pod (N = 538)
% 15.2 (12.4–18.5) 30.7 (26.2–35.3) 16.0 (13.2–19.1) 26.3 (22.7–30.3) 5.8 (4.1–7.9) 5.0 (3.4–7.2)
RR 0.71 (0.49–0.96) 0.99 (0.73–1.24) 1.00 (0.58–1.40) 1.31 (0.90–1.78) 5.00 (1.28–11.69) 0.71 (0.32–1.20)
Tank (N = 1801)
% 13.8 (12.3–15.4) 43.2 (41.1–45.6) 12.8 (11.4–14.4) 23.4 (21.8–25.3) 3.8 (3.0–4.8) 2.7 (2.0–3.5)
RR 0.64 (0.46–0.86) 1.39 (1.08–1.71) 0.80 (0.54–1.13) 1.17 (0.82–1.55) 3.27 (0.82–7.02) 0.38 (0.18–0.61)
Mod (N = 783)
% 11.1 (8.9–13.5) 50.0 (46.9–53.2) 10.6 (8.2–13.1) 22.8 (19.9–26.1) 4.0 (2.9–5.4) 1.5 (0.8–2.6)
RR 0.52 (0.36–0.73) 1.61 (1.27–2.02) 0.67 (0.44–0.94) 1.14 (0.77–1.53) 3.45 (0.59–8.08) 0.23 (0.10–0.46)
Smoking status
Smoker (N = 2266)
% 14.5 (13.1–16.2) 39.9 (38.0–41.9) 15.2 (13.9–16.6) 21.0 (19.4–22.9) 3.8 (3.1–4.7) 4.4 (3.7–5.2)
RR Ref Ref Ref Ref Ref Ref
Never smoker (N = 250)
% 23.4 (18.1–30.1) 40.3 (33.5–47.4) 9.3 (6.0–13.6) 18.0 (13.3–23.8) 7.0 (4.3–11.2) 2.8 (1.2–5.8)
RR 1.62 (1.17–2.02) 1.01 (0.83–1.18) 0.62 (0.40–0.90) 0.86 (0.61–1.10) 1.88 (1.04–2.87) 0.68 (0.19–1.23)
Ex-smoker (N = 1319)
% 11.8 (10.2–13.7) 43.2 (40.7–45.8) 10.8 (9.4–12.5) 28.4 (26.4–30.8) 4.2 (3.3–5.3) 1.5 (0.9–2.4)
RR 0.82 (0.68–0.96) 1.08 (1.01–1.18) 0.72 (0.58–0.83) 1.35 (1.19–1.51) 1.10 (0.81–1.49) 0.36 (0.19–0.54)
Table 3. Nicotine concentration used by frequency of use, device type and smoking status among e-cigarette
users. a Percentages are unweighted. b RR represents risk ratio. c Participants who used combinations of products
or NRT were excluded.
and more likely to use nicotine concentrations of ≤ 6 mg/ml and 12–19 mg/ml (Table 3). Use of non-nicotine
e-liquid was more common among users of disposable e-cigarette than of other device types. Mod and tank users
were more likely to use ≤ 6 mg/ml nicotine concentration than disposable e-cigarette users. Relative to never
smokers, smokers and ex-smokers were less likely to use non-nicotine e-liquid and nicotine concentrations of
≥ 20 mg/ml.
Discussion
Tank e-cigarettes were consistently the most commonly used device type in England from 2016 to 2020 among
adults who used HANDS. Mod e-cigarettes were the second most widely used device type until 2020, where
pod e-cigarettes overtook them. JUUL use rose year-on-year from 2018 to the extent that JUUL is used by 1
in 10 people who use HANDS in 2020. Heated tobacco product use remains relatively rare (3.4% of HANDS
users in 2016 versus 4.2% in 2020). Relative to non-daily e-cigarette users, daily users were more likely to use
tank e-cigarettes but less likely to use disposables. Relative to HANDS users who were current smokers, those
who were ex-smokers were more likely to use mod and tank e-cigarettes, but less likely to use pods, disposables,
JUUL and heated tobacco products. In addition, prevalence of JUUL and heated tobacco product use was higher
among HANDS users who were never smokers than ex- or current smokers. Across all years, the majority of
e-cigarette users (> 80%) used e-liquid that contained nicotine, but lower nicotine concentrations (≤ 6 mg/ml)
were most common. Daily e-cigarette users were less likely than non-daily users to use non-nicotine e-liquid.
Relative to HANDS users who were ex- or current smokers, those who had never smoked were more likely to
use both non-nicotine and high nicotine (≥ 20 mg/ml) e-liquid.
Comparison of these results with previous studies highlights differences between England and other
countries42–44. Tank e-cigarettes have remained the most commonly used device type in England, while in the
US pod e-cigarettes have become the most popular—primarily driven by the rise in JUUL use18. In the US,
JUUL were widely and successfully marketed but advertising was much more limited in England by EU TPD
regulations18. Pod e-cigarette and JUUL use rose modestly in England from 2019 to 2020. These differences could
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arise from the 20 mg/ml cap on nicotine concentration in e-cigarettes in the EU, which may have undermined
how pod e-cigarettes with nicotine salts allow users to vape high nicotine concentrations without irritation to the
throat3,19. However, an important recent product development may have changed this. JUUL have altered their
products for the EU market such that each puff generates a greater volume of aerosol than equivalent products
in America. Thus, products in both markets provide similar amounts of nicotine per puff despite using e-liquids
with lower nicotine concentrations (18 mg/ml in EU versus 58 mg/ml in US)45. This change, enacted in summer
2019, may be one factor that has contributed to the recent increased prevalence of JUUL use in England. Further
monitoring is required.
We found that use of heated tobacco products has remained relatively rare in England from 2016 to 2020,
unlike in Japan and South Korea where these products have become increasingly p opular24,46,47. This might result
from England already having a well-established e-cigarette market when heated tobacco products launched in
the country. Disposable cigarette use also remains rare in England, which is possibly a result of these products
having poor nicotine delivery compared with other e-cigarettes4. Recently, a new type of disposable e-cigarette
has entered markets across the world, which has a similar USB drive shape to pod devices48. These products use
nicotine salts at similar concentrations to pod e-cigarettes like JUUL, and user reports suggest they may provide
a stronger ‘hit’ than other disposable p roducts48. This innovation may explain recent data showing an increase
in use of disposable products among US y ouths49. Future research should track whether there are similar rises
in the popularity of these disposable e-cigarettes in England.
As may be expected due to EU TPD r egulation50, use of high nicotine concentrations (≥ 20 mg/ml) in Eng-
land was rare. In fact, low (≤ 6 mg/ml) nicotine concentrations were most p opular51. Although greater use of
low nicotine concentrations may appear to benefit public health, the opposite may be the case. People tend to
self-titrate their e-cigarette use to reach a desired nicotine level22,23. Thus, users of low nicotine concentration
e-liquid may use their device more frequently, with longer puffs, and at hotter temperatures than those using
high nicotine concentration e-liquids52, which could increase their risk of harm.
A sizeable minority of e-cigarette users (one-in-seven) reported using e-liquid without nicotine. However,
as participants were asked for the nicotine concentration they “mainly use”, many of these individuals may have
also used e-liquid with nicotine. This is especially important because shortfills—large bottles of non-nicotine
e-liquids that are topped up with nicotine shots—are widely available in England. These shortfills allow users to
circumvent the 10 ml bottle size cap for nicotine e-liquid introduced under EU TPD r egulation50. Future research
should measure whether participants use combinations of nicotine concentrations, to see the proportion of
e-cigarette users that exclusively use e-liquid without nicotine.
We found differences in product use according to the frequency with which people vape. Relative to non-daily
users, daily e-cigarette users were less likely to use disposable and pod devices and more likely to use tanks. This
could indicate that people who try disposable e-cigarettes are unlikely to transition to more frequent use, pos-
sibly a result of them being less satisfying than other e-cigarettes53. Alternatively, frequent vapers may seek out
products that are cheap to refill, like tanks, whereas those who vape infrequently may be more concerned about
upfront cost of the e-cigarette device, preferring pods and d isposables54,55. Non-daily e-cigarette users were more
likely to use non-nicotine e-cigarettes than daily users. This is unsurprising given that nicotine is the primary
dependence-inducing compound in e-cigarettes, which means use of non-nicotine products is unlikely to lead
to dependence or more frequent use. It also indicates that, while 14% of e-cigarette users reported mainly using
non-nicotine e-liquid, people used them less frequently, so the percentage share of the e-liquid market held by
nicotine-free products is likely much lower than this.
There were also differences by smoking status. Pod, disposable, JUUL and HTP e-cigarette use was less com-
mon among HANDS users who were ex-smokers than current smokers. This might indicate that smokers who use
these devices are less likely to quit smoking cigarettes. However, given the cross-sectional design of this study, it
is difficult to infer how effective these products are for smoking cessation from these associations. An alternative
explanation is that the convenience of pods and disposables relative to tanks and mods attracts people who want
to use e-cigarettes to manage cravings to smoke rather than quit. Prevalence of JUUL and HTP use was higher
among HANDS users who were never smokers than among those who were ex- or current smokers. However,
this high prevalence was primarily driven by data from a single month in a specific local authority area, suggest-
ing the difference may arise from a localised effect. Compared with current and ex-smokers, never smokers who
used HANDS were more likely to use non-nicotine e-liquid. This is consistent with previous results showing
minimal signs of nicotine dependence in e-cigarette users who have never smoked56. Prevalence of use of high
(≥ 20 mg/ml) nicotine concentrations was low regardless of smoking status, but it was relatively higher among
e-cigarettes users who were never smoker compared with those who were current or former smokers. However,
there were very few never smokers in our sample, so this difference may be artefactual.
This study benefitted from using a representative sample of the population in England, having a pre-registered
analysis plan, and measuring detailed information on participants’ usage of e-cigarettes, heated tobacco products
and cigarettes. It also benefitted from the use of Bayesian 95% credible intervals, which possess the properties
that researchers often misinterpret frequentist confidence intervals as having (i.e. there is a 95% probability that
the true parameter value lies within the 95% credible interval, given the data and assumptions)57,58. However,
there were several limitations. Firstly, participants who used combinations of HANDS device types and/or NRT
(N = 377) were not asked about the nicotine concentration and frequency of use for each product separately,
so they had to be excluded from some analyses. Secondly, there were less data for 2016 and 2020 than for other
years, which meant that there was greater uncertainty around prevalence estimates. Results for these years may
also differ from other years if product use varies across seasons, as estimates were calculated on data from only
a few months in the year. In an unplanned sensitivity analysis, we found similar proportions of vapers using
each product across all months, suggesting seasonality had little effect on results. Thirdly, there were very few
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participants surveyed among some subgroups (e.g. HANDS users who had never smoked), which meant there
was large uncertainty around prevalence estimates.
Conclusions
In England, choices of HANDS device types have remained relatively stable from 2016 to 2020, with tank e-cig-
arettes consistently the most widely used device type. Use of JUUL and heated tobacco products remains rare
among HANDS users; however, there is some evidence JUUL use is becoming more common. Daily e-cigarette
users were less likely to use disposable products. The vast majority of e-cigarette users used e-liquid that con-
tained nicotine, but lower nicotine concentrations (≤ 6 mg/ml) were most popular. Relative to HANDS users
who currently smoked, those who were ex-smokers were more likely to use mod and tank e-cigarettes, but less
likely to use pods, disposables, JUUL and heated tobacco products. The e-cigarette and heated tobacco industries
are adapting rapidly, with new innovations introduced each year. Regulations, such as nicotine caps, appear to
shape which products people use. It is therefore essential that we continue to track the popularity of different
devices and how it changes alongside a shifting regulatory landscape.
Data availability
Data are available upon reasonable request.
Received: 14 January 2021; Accepted: 28 May 2021
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Acknowledgements
HTB holds a PhD studentship that is funded by Public Health England (558585/180737). Cancer Research UK
provided funding for the data collection and salaries for SJ and JB (C1417/A22962). Authors are members of
the UK Prevention Research Partnership SPECTRUM Consortium, an initiative funded by UK Research and
Innovation Councils, the Department of Health and Social Care (England) and the UK devolved administrations,
and leading health research charities. The funders had no final role in the study design; in the collection, analysis
and interpretation of data; in the writing of the report; or in the decision to submit the paper for publication.
All researchers listed as authors are independent from the funders and all final decisions about the research
were taken by the investigators and were unrestricted. All authors had full access to all of the data (including
statistical reports and tables) in the study and take responsibility for the integrity of the data and HTB for the
accuracy of the data analysis.
Author contributions
H.T.B., J.B., L.S. and S.J. each substantially contributed to the conception, design, drafting and editing for this
study. H.T.B. performed the data analysis.
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Competing interests
Authors declare no financial links with manufacturers of tobacco products or e-cigarettes or their representatives.
JB and LS have received unrestricted funding from companies who manufacture smoking cessation medications
to study smoking cessation outside of this work. LS has also received personal fees from Johnson & Johnson
(as a member of the advisory board) outside the submitted work. HTB and SJ declare no competing interests.
Additional information
Supplementary Information The online version contains supplementary material available at https://doi.org/
10.1038/s41598-021-92617-x.
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